Part I. Reactive Epoxides: Several Epoxides derived from aromatic systems will be synthesized and characterized both chemically and biologically. In particular, we wish to understand factors which govern the relative rates of rearrangement and nucleophilic addition to epoxides which may serve as alkylating agents in vivo. Part II. Studies of Oxygen Transfer. The flavin coenzyme system will be examined for the ability to transfer oxygen to various substrates using chemical model systems to mimic in vivo activity. Models for flavin-based oxaziridines and nitroxyl radicals will be studied. Oxaziridines will be examined in detail for the ability to transfer oxygen to amines. Part III. Reactive Crown Ethers. Studies will focus on the ability of functionalized crown ethers to bind and selectively react with substrates.